The metathesis reaction has been widely used in various industrial areas, e.g., for synthesis of monomers for the medical area, and production of molded articles excellent in mechanical strength, heat resistance, dimensional stability or the like by ring-opening polymerization in a mold, e.g., by reaction injection molding (hereinafter sometimes referred to as RIM), of a norbornene-based monomer, e.g., dicyclopentadiene (hereinafter sometimes referred to as DCPD), which is a typical representative monomer for metathesis polymerization.
The conventional metathesis process uses a catalyst which exhibits the metathesis activity by reacting the catalyst precursor for the active catalyst, e.g., molybdenum or tungsten, with an alkyl metal in a system, as disclosed by, e.g., Japanese Patent No.3,038,825. However, such a process is greatly limited by, e.g., reaction environments, because the alkyl metal is a water-reactive reagent.
Japanese Patent Laid-Open No.11-510807 discloses a ruthenium-based metathesis catalyst as the one which can solve the above problems. It has been attracting attention as a catalyst exhibiting excellent metathesis activity without being deactivated even in the presence of moisture or oxygen. However, it is not activated as an alkyl metal or the like in a system but exhibits activity as a single complex compound. As a result, the reaction starts as soon as it is brought into contact with a metathesis-reactive monomer, to cause problems, one of which is dispersion of the catalyst or the like becoming the rate-determining step. This may be a detrimental problem when a crosslinkable monomer, e.g., dicyclopentadiene, is to be polymerized, because this can greatly limit the process operation or fluctuate properties of the product polymer. One of the commonly known countermeasures is incorporation of triphenyl phosphine or the like in the system to retard the polymerization process. This, however, may cause problems related to product safety, resulting from contamination of the product with phosphorus or the like.
It is an object of the present invention to provide a novel organometallic compound excellent in stability to oxygen, metathesis reactivity and reaction controllability, in order to solve the above problems. It is another object of the present invention to provide a process for producing the same. It is still another object of the present invention to provide a metathesis reaction catalyst containing the same. It is still another object of the present invention to provide a polymerization process using the same catalyst. It is still another object of the present invention to provide a polymer produced by the same polymerization process.